This is a collaborative research program being performed with Dr. David Mann of the American Red Cross, Rockville, Maryland as part of a scientific program investigating the structure and function of the novel antimicrobial domain of the iron-binding host defense protein, lactoferrin (LF). Our specific efforts are directed towards an assessment of the microbiological effects of a LF peptide, in particular, its defensin-like properties as they pertain to mycobacteria. The aims are to: (1) measure the bactericidal effects of the LF-defensin on various species of mycobacteria; (2) investigate the synergistic bacteriocidal effect of LF-defensin and anti-mycobacterial drugs on mycobacteria and; (3) develop strategies for delivering defensins, as potentiators of anti-mycobacterial drugs and for the effective killing of mycobacteria residing within host cells.